Abstract: The invention relates to a server system for providing at least one service. The system having an interface for connecting a server to a user's computer, an authentication device that is designed and provided for request personal identification data of a user who logs onto the server via the user computer and to permit the user computer access if authentication is successful, and a server protection system. The server protection system is designed and provides to compare additional user's computer specific identification data with identification data stored in advance on the server, after successful authentication by the authentication device, and to grant authorization to the user's computer to access the service or services depending on the comparison of the user's computer specific identification data. The invention also relates to a method for providing at least one service and the method for executing an application program.

Abstract: A system is disclosed comprising multiple sets of client computers each client computer having installed thereon an application program The application program comprising client computer specific log-in information, a database system coupled to the set of client computers via a network. The database system having a log-in component for logging-in the client computers, and being partitioned into multiple relational databases each one of which is assigned to one set of the sets of client computers. Each database further storing encrypted data items, each data item being encrypted with one of the user or user-group specific cryptographic keys, the key identifier of the cryptographic key with which one of the data items is encrypted being stored in the database as an attribute of the one of the encrypted data items. The log-in component comprising assignment information indicative of the assignment of the databases to the set of client computers.

Abstract: The invention relates to a method for creating a set of asymmetrical cryptographic key pairs, wherein the set of key pairs has a first key pair (K1) and a second key pair (K2), wherein the first key pair is formed by a first private (G1) and a first public key (O1) and the second key pair is formed by a second private (G2) and a second public key (O2), wherein a first cipher (C_G2_O1) is allocated to the first and second key pair, wherein the first cipher is formed by an encryption of the second private key (G2) with the first public key (O1), having the following steps: adding a third asymmetrical cryptographic key pair (K3) to the set of key pairs, wherein the third key pair is formed by a third private (G3) and a third public key (O3); creating a second cipher (C_G3_O1) by encrypting the third private key (G3) with the first public key (O1); storing the second cipher (212; 186), wherein the set of key pairs has a directed graph structure.

Abstract: A system is disclosed comprising multiple sets of client computers each client computer having installed thereon an application program The application program comprising client computer specific log-in information, a database system coupled to the set of client computers via a network. The database system having a log-in component for logging-in the client computers, and being partitioned into multiple relational databases each one of which is assigned to one set of the sets of client computers. Each database further storing encrypted data items, each data item being encrypted with one of the user or user-group specific cryptographic keys, the key identifier of the cryptographic key with which one of the data items is encrypted being stored in the database as an attribute of the one of the encrypted data items. The log-in component comprising assignment information indicative of the assignment of the databases to the set of client computers.

Abstract: The invention relates to a method for creating a set of asymmetrical cryptographic key pairs, wherein the set of key pairs has a first key pair (K1) and a second key pair (K2), wherein the first key pair is formed by a first private (G1) and a first public key (O1) and the second key pair is formed by a second private (G2) and a second public key (O2), wherein a first cipher (C_G2_O1) is allocated to the first and second key pair, wherein the first cipher is formed by an encryption of the second private key (G2) with the first public key (O1), having the following steps: adding a third asymmetrical cryptographic key pair (K3) to the set of key pairs, wherein the third key pair is formed by a third private (G3) and a third public key (O3); creating a second cipher (C_G3_O1) by encrypting the third private key (G3) with the first public key (O1); storing the second cipher (212; 186), wherein the set of key pairs has a directed graph structure.

Abstract: A database system comprising: a memory containing multiple data records, wherein each of the data records has a data record asymmetric key pair for cryptographic encryption and decryption, wherein each data record asymmetric key pair comprises a data record public key and a data record private key, wherein the data contained in each of the multiple data records is encrypted by the data record public key, wherein the data record private key of each data record asymmetric key pair is encrypted with the public key of another asymmetric key pair; a set of user accounts, wherein each of the user accounts has a user asymmetric key pair for encryption and decryption, wherein each user asymmetric key pair has a user public key and a user private key; wherein data is added to a data record by encrypting it with the data record public key; wherein access to the data record is granted to a user account by encrypting the data record private key with the public key of an asymmetric cryptographic key pair whose encrypted p

Abstract: A system is disclosed comprising multiple sets of client computers each client computer having installed thereon an application program. The application program comprising client computer specific log-in information, a database system coupled to the set of client computers via a network. The database system having a log-in component for logging-in the client computers, and being partitioned into multiple relational databases each one of which is assigned to one set of the sets of client computers. Each database further storing encrypted data items, each data item being encrypted with one of the user or user-group specific cryptographic keys, the key identifier of the cryptographic key with which one of the data items is encrypted being stored in the database as an attribute of the one of the encrypted data items. The log-in component comprising assignment information indicative of the assignment of the databases to the set of client computers.

Abstract: A system is disclosed comprising multiple sets of client computers each client computer having installed thereon an application program The application program comprising client computer specific log-in information, a database system coupled to the set of client computers via a network. The database system having a log-in component for logging-in the client computers, and being partitioned into multiple relational databases each one of which is assigned to one set of the sets of client computers. Each database further storing encrypted data items, each data item being encrypted with one of the user or user-group specific cryptographic keys, the key identifier of the cryptographic key with which one of the data items is encrypted being stored in the database as an attribute of the one of the encrypted data items. The log-in component comprising assignment information indicative of the assignment of the databases to the set of client computers.

Abstract: An apparatus for encrypting data is provided. The apparatus is capable of symmetrically encrypting data and then encrypting the symmetrically encrypted data with the aid of a bit string. The bit string has a maximum entropy. Encryption of the symmetrically encrypted data is designed such that a section of the bit string is used for encryption and successive encryption operations are carried out with carrying sections of the bit string while the bit string remains unchanged.

Abstract: The invention relates to a computer implemented method for analyzing data of a first user, wherein an asymmetric cryptographic key pair is associated with the first user, said asymmetric cryptographic key pair comprising a public key and a private key, the data being stored pseudonymously in a database with the data being assigned to an identifier, wherein the identifier comprises the public key, the method comprising: receiving a set of rules, the set of rules describing data processing steps, receiving the identifier, retrieving the data assigned to the identifier from the database, analyzing the retrieved data by applying the set of rules, providing a result of the analysis.

Abstract: The invention relates to a computer implemented method for performing cloud computing on data of a first user employing cloud components, the cloud components comprising a first database and a data processing component, wherein an asymmetric cryptographic key pair is associated with the first user, said asymmetric cryptographic key pair comprising a public key and a private key, the data being stored pseudonymously non-encrypted in the first database with the data being assigned to an identifier, wherein the identifier comprises the public key, the method comprising retrieving the data from the first database by the data processing component, wherein retrieving the data from the first database comprises receiving the identifier and retrieving the data assigned to the identifier from the first database, wherein the method further comprises processing the retrieved data by the data processing component and providing a result of the analysis.

Abstract: A computer system comprising multiple sets of client computers coupled to a database system via a network. Each client computer having installed thereon an application program that comprises client computer specific log-in information. The database system having a log-in component for logging-in the client computers, and being partitioned into multiple relational databases. Each one of the relational databases being assigned to one set of the sets of client computers. Each one of the relational databases storing encrypted data items. Each data item being encrypted with one of the user or user-group specific cryptographic keys. A key identifier of the cryptographic key with which one of the data items is encrypted being stored in the relational database as an attribute of the one of the encrypted data items. The log-in component comprising assignment information indicative of the assignment of the databases to the set of client computers.

Abstract: The invention relates to a computer implemented method for generating a pseudonym for a user comprising entering a user-selected secret, storing the user-selected secret in memory, computing a private key by applying an embedding and randomizing function onto the secret, storing the private key in the memory, computing a public key using the private key, the public key and the private key forming an asymmetric cryptographic key, erasing the secret and the private key from the memory, and outputting the public key for providing the pseudonym.

Abstract: The invention relates to a computer implemented method for generating a set of identifiers from a private key, the method comprising the steps of: calculating a set of public keys, wherein the private key and each public key of the set of public keys form an asymmetric cryptographic key pair; and outputting the identifiers comprising the public keys.

Abstract: The invention relates to a computer implemented method for analyzing data of a first user, wherein an asymmetric cryptographic key pair is associated with the first user, said asymmetric cryptographic key pair comprising a public key and a private key, the data being stored pseudonymously in a database with the data being assigned to an identifier, wherein the identifier comprises the public key, the method comprising: receiving a set of rules, the set of rules describing data processing steps, receiving the identifier, retrieving the data assigned to the identifier from the database, analyzing the retrieved data by applying the set of rules, providing a result of the analysis.

Abstract: The invention relates to a method for creating a second asymmetric cryptographic pair of keys, wherein a first private key (G0) together with a first public key (O0) forms a first asymmetric cryptographic pair of keys (K0). Embodiments of the method may comprise the following steps: receiving a user identifier; calculating a second private key (G1), wherein a random value (z) and the user identifier are considered in the calculation; calculating a second public key (O1) from the second private key using an asymmetric cryptographic key creation method, wherein the second private key and the second public key form the second asymmetric cryptographic pair of keys (K1, 206); creating a first cipher (C_G0—O1) by encrypting the first private key (G0) with the second public key (O1); and storing the first cipher (C_G0—O1).

Abstract: An apparatus for encrypting data is provided. The apparatus is capable of symmetrically encrypting data and then encrypting the symmetrically encrypted data with the aid of a bit string. The bit string has a maximum entropy. Encryption of the symmetrically encrypted data is designed such that a section of the bit string is used for encryption and successive encryption operations are carried out with varying sections of the bit string while the bit string remains unchanged.

Abstract: The invention relates to a computer implemented method for sending a message to a recipient user, wherein a recipient asymmetric cryptographic key pair is associated with the recipient user, said key pair comprising a public recipient key and a private recipient key, the method comprising sending the message to said recipient user with the recipient address to which the message is sent comprising the public recipient key.

Abstract: The invention relates to a computer implemented method for performing cloud computing on data of a first user employing cloud components, the cloud components comprising a first database and a data processing component, wherein an asymmetric cryptographic key pair is associated with the first user, said asymmetric cryptographic key pair comprising a public key and a private key, the data being stored pseudonymously non-encrypted in the first database with the data being assigned to an identifier, wherein the identifier comprises the public key, the method comprising retrieving the data from the first database by the data processing component, wherein retrieving the data from the first database comprises receiving the identifier and retrieving the data assigned to the identifier from the first database, wherein the method further comprises processing the retrieved data by the data processing component and providing a result of the analysis.

Abstract: The invention relates to a method for creating a second asymmetric cryptographic pair of keys (206), wherein a first private key (G0, 154) together with a first public key (O0, 126) forms a first asymmetric cryptographic pair of keys (K0, 218), wherein the method comprises the following steps: receiving a user identifier; calculating a second private key (G1), wherein a random value (z) and the user identifier are considered in the calculation; calculating a second public key (O1) from the second private key using an asymmetric cryptographic key creation method, wherein the second private key and the second public key form the second asymmetric cryptographic pair of keys (K1, 206); creating a first ciphertext (C_G0—O1, 212; 186) by encrypting the first private key (G0) with the second public key (O1); storing the first ciphertext (C_G0—O1, 212; 186).